They looked into this concept a while back and came to the conclusion that unless the population density was great enough along the guideway, the maintenance cost was too high.
The U.S. seems to be able to maintain a quite impressive railroad system for freight purposes, in what is still the largest rail transport network of any country in the world. Passenger transport withered away as long-distance road travel and cheap air flights out-competed it. With sufficient ingenuity and capital expenditure, I wonder if perhaps it could be revived?